1. Technical Field
The present invention relates to an inflator, and particularly relates to an inflator for an inflatable vehicle occupant protection device, such as an air bag.
2. Description of the Prior Art
An inflator for an inflatable vehicle occupant protection device, such as an air bag, may include a pressure vessel containing inflation fluid under pressure. Such an inflator is disclosed in U.S. Pat. No. 5,348,344. In the inflator disclosed in U.S. Pat. No. 5,348,344, the inflation fluid is an ingredient in a mixture of gases. The mixture of gases also includes a fuel gas which, when ignited, heats the inflation fluid. Rupturable wall portions of the pressure vessel, or burst discs, are used to seal the mixture of gases in the pressure vessel.
The inflator includes an igniter which is actuated electrically when the air bag is to be inflated. The igniter produces combustion products which, in turn, ignite the fuel gas in the pressure vessel. The fluid pressure inside the pressure vessel is increased by the heat generated upon combustion of the fuel gas. When the increasing fluid pressure reaches a predetermined elevated level, the burst disc ruptures as a result. The inflation fluid then flows outward from the pressure vessel and into the air bag to inflate the air bag.